Helena Drueke,
Helena Drueke
Institution: Institute of Physics, University of Rostock, 18051 Rostock, Germany
Email: helena.drueke@uni-rostock.de
Dieter Bauer
Dieter Bauer
Institution: Institute of Physics, University of Rostock, 18051 Rostock, Germany
Email: dieter.bauer@uni-rostock.de
"Periodic driving may cause topologically protected, chiral transport along edges of a 2D lattice that, without driving, would be topologically trivial. We study what happens if one adds a different on-site potential along the diagonal of such a 2D grid. In addition to the usual bulk and edge states...
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"Periodic driving may cause topologically protected, chiral transport along edges of a 2D lattice that, without driving, would be topologically trivial. We study what happens if one adds a different on-site potential along the diagonal of such a 2D grid. In addition to the usual bulk and edge states, the system then also exhibits doublon states, analogous to two interacting particles in one dimension. A particle initially located at an edge propagates along the system's boundary. Its wavefunction splits when it hits the diagonal and continues propagating simultaneously along the edge and the diagonal. The strength of the diagonal potential determines the ratio between both parts. We show that for specific values of the diagonal potential, hopping onto the diagonal is prohibited so that the system effectively separates into two triangular lattices. For other values of the diagonal potential, we find a temporal delay between the two contributions traveling around and through the system. This behavior could enable the steering of topologically protected transport of light along the edges and through the bulk of laser-inscribed photonic waveguide arrays."
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1 year ago
Meir Shimon
Meir Shimon
Institution: School of Physics and Astronomy, Tel Aviv University,
Email: meirs@tauex.tau.ac.il
In the standard cosmological model the dark energy (DE) and nonrelativistic (NR) matter densities are determined to be comparable at the present time, in spite of their greatly different evolution histories. This ‘cosmic coincidence’ enigma could be explained as a non-anthropic observational se...
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In the standard cosmological model the dark energy (DE) and nonrelativistic (NR) matter densities are determined to be comparable at the present time, in spite of their greatly different evolution histories. This ‘cosmic coincidence’ enigma could be explained as a non-anthropic observational selection effect: We show that in a suitably chosen frame the Universe is at its most probable epoch when the Hubble radius attains a maximum, at the epoch when the energy densities of DE and NR
matter are comparable.
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2 years ago
Oleg Lebedev,
Oleg Lebedev
Institution: Department of Physics and Helsinki Institute of Physics, Gustaf Hallstromin katu 2a, FI-00014
Email: info@res00.com
Jong-Hyun Yoon
Jong-Hyun Yoon
Institution: Department of Physics and Helsinki Institute of Physics, Gustaf Hallstromin katu 2a, FI-00014
Email: info@res00.com
We consider dark matter production during the inflation oscillation epoch. It is conceivable that renormalizable interactions between dark matter and inflation may be negligible. In this case, the leading role is played by higher dimensional operators generated by gravity and thus suppressed by the ...
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We consider dark matter production during the inflation oscillation epoch. It is conceivable that renormalizable interactions between dark matter and inflation may be negligible. In this case, the leading role is played by higher dimensional operators generated by gravity and thus suppressed by the Planck scale. We focus on dim-6 operators and study the corresponding particle production in perturbative and non–perturbative regimes. We find that the dark matter production rate is dominated by non–derivative operators involving higher powers of the inflation field. Even if they appear with small Wilson coefficients, such operators can readily account for the correct dark matter abundance.
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2 years ago
Joseph E Brierly
Joseph E Brierly
Institution: Joseph E Brierly, Ph.D., Wayne State University,
Email: jbrierly@comcast.net
This article gives a overall picture of how the universe works from the likelihood that our universe is infinite dimensional at the nanometer scale of an indestructible quark. The article explains that we only can perceive for sure up to 4 dimensions of physical reality. However, the speculation in ...
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This article gives a overall picture of how the universe works from the likelihood that our universe is infinite dimensional at the nanometer scale of an indestructible quark. The article explains that we only can perceive for sure up to 4 dimensions of physical reality. However, the speculation in this article seems very clear that likely we are seeing activity in the 5th dimension in particle physics experimentation explaining the EPR paradox and other mysteries seen in particle physics. Finally, the article shows why the Mendeleev Chart has historically listed possible stable atoms without giving the exact number possible. The way protons and other hadrons are composed of six quarks and six antiquarks held together by gluons leads to the inevitable conclusion that
only 108 stable atoms can exist. Being stable means the protons in an atom are composed of 3 quarks/antiquarks having charge 1. Recent discoveries in particle physics research demonstrates that there exists a particle named the pentaquark composed of five quarks. The article explains that pentaquarks have been identified in recent particle research. It is not known yet whether the pentaquark leads to a different proton that leads in turn to a pentaquark atom. New particle research will likely answer this question.
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2 years ago
Robert J Buenker Buenker
Robert J Buenker Buenker
Institution: Faculty of C-Mathematics and Natural Sciences, Bergische Universität Wuppertal,
Email: rjbuenker@gmail.com
A number of the most often cited results of relativity theory deal with the relationships between energy, momentum and inertial mass. The history of how Einstein and Planck came to these conclusions is reviewed. It is pointed out that considerations of how the speed of light is affected by the motio...
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A number of the most often cited results of relativity theory deal with the relationships between energy, momentum and inertial mass. The history of how Einstein and Planck came to these conclusions is reviewed. It is pointed out that considerations of how the speed of light is affected by the motion of the Earth played a determining role in these developments. After the Michelson-Morley null-interference result became available, Voigt introduced a new space-time transformation by amending the classical Galilean transformation so that the speed of light in free space has the same value of c regardless of the state of motion of both the light source and the observer. This led to the Lorentz transformation which has been the cornerstone of relativity theory for
the past century. A thought experiment is presented which proves, however, that there are many situations for which the measured speed of light is NOT equal to c. Furthermore, it is pointed out that the rate of an inertial clock cannot change spontaneously, which result is perfectly compatible with Newton’s First Law of Kinetics (Law of Inertia). This result contradicts the space-time mixing characteristic of the Lorentz transformation and leads to the conclusion that events which are spontaneous for one inertial frame will also be so for every other one. The uniform scaling procedure is a generalization of this result for all other physical properties than elapsed times. Its application shows that the commonly accepted relationships between energy and momentum are
only special cases in which it is assumed that the observer is stationary in the rest frame in which force has been applied to cause the object’s acceleration
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2 years ago
Berov G Lyubomir
Berov G Lyubomir
Institution: Engineer, Independent Innovative Ideas Researcher, Smolyan 4700,
Email: my_kaly1@mbox.contact.bg
The present, at any particular moment, is the realization of one of the many intentions of the All-creating Intellect. Here "realization" specifically means the materialization or the appearance of an object in the material world, which had not existed until now. This newly born material object exis...
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The present, at any particular moment, is the realization of one of the many intentions of the All-creating Intellect. Here "realization" specifically means the materialization or the appearance of an object in the material world, which had not existed until now. This newly born material object exists only for the duration of the moment of "now". This moment is infinitely short, or, if we use a concept from calculus, it is infinitesimal in duration. In my hypothesis, this new object is a product of a specific energy field of the All-creating Intellect. We call this particular energy field Time.
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2 years ago
It is widely believed that Hawking radiation originates from excitations near the horizons of black holes [1,2,3]. However, Giddings [2] proposed that the Hawking radiation spectrum that characterizes evaporating semi-classical black holes originates from a quantum “atmosphere”, which extends be...
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It is widely believed that Hawking radiation originates from excitations near the horizons of black holes [1,2,3]. However, Giddings [2] proposed that the Hawking radiation spectrum that characterizes evaporating semi-classical black holes originates from a quantum “atmosphere”, which extends beyond the horizon of a black hole. Although several research projects have been conducted in this field, they have not yet taken into account the effect of Rényi entropy. In the present article, we will therefore consider the effect of Rényi entropy on Hawking radiation power. We assume that if the effect of Rényi entropy is very small, we suggest that the Hawking radiation should originate from the quantum “atmosphere” which extends beyond the black hole’s horizon for finite dimensions. That is, that Giddings’ suggestion is the more likely of the above possibilities. However, for infinite dimensions, both suggestions are equally credible. We briefly consider the very large effect of Rényi entropy on Hawking radiation power as well. We find that if the effect of Rényi entropy is very large and ω/TBH is very small, then the power spectral density SR is proportional to the power spectral density SBH.
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2 years ago
Kamila Sieja
Kamila Sieja
Institution: Institute Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (CNRS, UMR7178),
Email: la.sieja@iphc.cnrs.fr
Neutron-rich Sr nuclei around N = 60 exhibit a sudden shape transition from a spherical ground state to strongly prolate-deformed. Recently, much new insight into the structure of Sr isotopes in this region has been gained through experimental studies of the excited levels, transition strengths, and...
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Neutron-rich Sr nuclei around N = 60 exhibit a sudden shape transition from a spherical ground state to strongly prolate-deformed. Recently, much new insight into the structure of Sr isotopes in this region has been gained through experimental studies of the excited levels, transition strengths, and spectroscopic factors. In this work, a “classic” shell model description of strontium
isotopes from N = 50 to N = 58 is provided, using a natural valence space outside the 78Ni core. Both even–even and even–odd isotopes are addressed. In particular, spectroscopic factors are computed to shed more light on the structure of low-energy excitations and their evolution along the Sr chain. The origin of deformation at N = 60 is mentioned in the context of the present and previous shell model and Monte Carlo shell model calculations.
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2 years ago
In this paper we consider the correspondence between the tachyon dark energy model and the Tsallis holographic dark energy scenario in an FRW universe. We demonstrate the Tsallis holographic description of tachyon dark energy in an FRW universe and reconstruct the potential and basic results of the ...
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In this paper we consider the correspondence between the tachyon dark energy model and the Tsallis holographic dark energy scenario in an FRW universe. We demonstrate the Tsallis holographic description of tachyon dark energy in an FRW universe and reconstruct the potential and basic results of the dynamics of the scalar field which describe the tachyon cosmology. In a flat universe, in the tachyon model of Tsallis holographic dark energy, independently of the existence of interaction between dark energy and matter or not, T˙ 2 must always be zero. Therefore, the equation of state ωD is always −1 in such a flat universe. For a non-flat universe, T˙ 2 cannot be zero so that ωD 6= −1 which cannot be used to explain the origin of the cosmological constant. T˙ 2 monotonically decreases with the increasing of cos(Rh/a) and cosh(Rh/a) for different δs. In particular, for an open universe, T˙ 2 is always larger than zero while for a closed universe, T˙ 2 is always smaller than zero which is physically invalid. In addition, we conclude that with the increasing of cos(Rh/a) and cosh(Rh/a), T˙ 2 always decreases monotonically for irrespective of the value of b2.
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2 years ago
Anand K. Bhatia
Anand K. Bhatia
Institution: Heliophysics Science Division, NASA/Goddard Space Flight Center,
Email: d.k.bhatia@nasa.gov
The excitation cross-sections of the nS states of atomic hydrogen, n = 2 to 6, by electron
impact on the ground state of atomic hydrogen were calculated using the variational polarizedorbital method at various incident electron energies in the range 10 to 122 eV. Converged excitation
cross-sectio...
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The excitation cross-sections of the nS states of atomic hydrogen, n = 2 to 6, by electron
impact on the ground state of atomic hydrogen were calculated using the variational polarizedorbital method at various incident electron energies in the range 10 to 122 eV. Converged excitation
cross-sections were obtained using sixteen partial waves (L = 0 to 15). Excitation cross-sections to
2S state, calculated earlier, were calculated at higher energies than before. Results obtained using
the hybrid theory (variational polarized orbital method) are compared to those obtained using other
approaches such as the Born–Oppenheimer, close-coupling, R-matrix, and complex-exterior scaling
methods using only the spherical symmetric wave functions. Phase shifts and elastic cross-sections
are given at various energies and angular momenta. Excitation rate coefficients were calculated at
various electron temperatures, which are required for plasma diagnostics in solar and astrophysics to
infer plasma parameters. Excitation cross-sections are compared with those obtained by positron
impact excitation.
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2 years ago